Abstract
A 43-year-old woman was refered for evaluation of a mass shadow noted on routine chest roentgenogram. She had no respiratory and circulatory symptoms. There was no critical episode in her past illness nor family history. Also, no abnormality had been pointed out at birth. Physical examination revealed no abnormality except bradycardia of 50/min. The electrocardiogram showed a regular sinus rhythm at a rate of 52/min, which was associated with occasional sinus arrest and junctional escape beats. The P wave was almost normal in shape. These findings suggested a sinus node dysfunction. On the P-A chest film, the azygos arch was dilatated to 2.0cm in transverse diameter at the junction of the trachea and the right main bronchus, along with the mass shadow in the left middle lung field. The CTR was 44%, and the shape of the heart was almost normal. On the lateral view, there was a shadow of a blood vessel between the lower back of the heart and the right diaphragm. Contrast angiogram showed a “candy cane” image due to anastomosis of the inferior vena cava with the superior vena cava through the azygos vein on the lateral view. Backward flow from the right atrium into the hepatic vein revealed a direct connection between them on the frontal view. No other abnormalities were found. The pulmonary mass was surgically removed, and diagnosed as tuberculoma histopathologically. She has been followed up under a diagnosis of interruption of the inferior vena cava with azygos continuation. The pathogenesis of this malformation was discussed.
